Buttons not matching

Hi Tom and co,

I am using the studio theme and for some reason the buttons I use dont match.

I am using 1 in a call to action bar and there is 1 on the comment form both look exactly the same except when hovering. I want it to go to yellow with dark grey/black text on hover and it works but only for comment post buttons and not in the call to action bar (its hover text is white).

I am fairly confused and hoping you can shed some light on it please.

Included link and creds in url field.

Many thanks